First install velocityjs in your node_modules
npm install velocityjs
Now from your project (where the node_modules mentioned above exists) use browserify
browserify -r velocityjs > velocity.js
This will create a velocity.js file that you can include in your website directly. If you don't have browserify then do npm install -g browserify
Usage
In your webpage js file first require velocityjs
var velocityjs = require("velocityjs");
Now to get the templated html do
var renderedString = velocityjs.render(initialString,context)
Note that velocity does not care if your initial string was html or not, you need to ensure that

First install velocityjs in your node_modules
npm install velocityjs
Now from your project (where the node_modules mentioned above exists) use browserify
browserify -r velocityjs > velocity.js
This will create a velocity.js file that you can include in your website directly. If you don't have browserify then do npm install -g browserify
Usage
In your webpage js file first require velocityjs
var velocityjs = require("velocityjs");
Now to get the templated html do
var renderedString = velocityjs.render(initialString,context)
Note that velocity does not care if your initial string was html or not, you need to ensure that